In the current industrial automation age of rapid development, more and more processes need to be completed by higher-degree automation equipments. Moreover, with the continuous increase of labour cost, and a demand for better working environment, robotic products come into being. Cartesian-coordinate robot, as the name implies, is industrial automation robot equipment which takes the stereoscopic space formed by a spatial geometrical relationship along XYZ directions as the work space. In industrial applications, this equipment can be set according to different procedures, to realize automatic control and form a multi-purpose manipulator.
The Cartesian-coordinate robot mainly consists of four function modules, a linear motion unit, a driving unit, a control unit and an end operation unit. In order to reduce the cost of the Cartesian-coordinate robot, to shorten product R&D cycle, to improve the product reliability and performance, many countries in Europe and America have modularized the Cartesian-coordinate robot, and the linear motion unit is the most typical and most important unit in the modularization. The function of the linear motion unit is adding all motion elements to a whole movement unit, which is comprised of a motion support part (light bar or linear guide rail), a locating body profile part (various types of profiles), a transmission part (synchronous pulley, synchronous belt or lead screw) and a slide block motion part (which moves as the pulling of a synchronous belt or a leads crew nut).
With the continuous development of technology, people have proposed higher requirements such as high speed, high precision, high reliability, easy operability and maintainability on the performances of the Cartesian-coordinate robot. As the core unit of the Cartesian-coordinate robot, the performance of the linear motion unit, such as reliability, stability, operability and maintainability, receives more and more attentions of scientific and technical personnel; and the improvement of the performance of the linear motion unit mainly depends on the locating body profile part and the motion support part. The conventional locating body profile part is an assembly space cut out on the middle section of a common aluminium profile, for assembling a transmission unit, and the motion support part is directly laid in the assembly space. In this way, the mechanical structure of the original profile would be destroyed and the mechanical performance of the entire structure would be degraded too. Moreover, the conventional locating body profile part and the motion support part form a cantilever structure by adopting a single aluminium profile or form a frame structure by adopting double aluminium profiles; however, long-period actual experiences show that the two mechanical structures abased on aluminium profile are easy to suffer different degrees of deflection deformation and twist deformation, and the impact resistance is relatively low when the robot is moving with a relatively high speed. These defects are very fatal for a Cartesian-coordinate robot linear motion system which is required of high performances, high reliability and high precision.
Therefore, it is necessary to provide a linear motion unit which has a stable mechanical structure and a high impact resistance, and can reduce deflection deformation and twist deformation.